Some Induced-Pressure Measurements in a High-Rise Office Building

Induced-pressure measurements were made in the tower of an eleven-story office building using a fan of 7.55-m3/s capacity. The fan was used to depressurize the entire tower as well as a single floor. Sulfur hexafluoride (SF6) tracer gas was used to trace air movements from floor to floor during single-floor depressurization.

Average flow coefficients of approximately 5 × 10−4 m3/m2 · s · Pa0.65 for the tower and 7 × 10−4 m3/m2 · s · Pa0.65 for the single floor were estimated from single point measurements. The effect of opening and closing office doors also was determined.

By simultaneous solution of flow equations for the whole tower and a single floor, it was estimated that about 80 to 90% of the airflow during depressurization of a single floor came from floors above and below. From SF6 tracer gas measurements, it was estimated that about 50% of the flow could be traced to the floor below.

The pressure difference measurements upon which the previous estimates are based were in the 3- to 10-Pa range. Uncertainties in the estimates of flow coefficients and air-flow from above and below are discussed in the text. The results essentially are descriptive, but they suggest an experimental approach to the determination of flow coefficients for modeling through the wall and for floor-to-floor components of airflow in building ventilation.